Document ITU-T G.807 “Requirements for automatic switched transport networks” by the ITU describes requirements for Automatic Switched Transport Networks (ASTN). This document has been withdrawn and its content has been merged into document ITU-T G.8080 “Architecture of the Automatic Switched Optical Network (ASON)” by the ITU describing an Automatic Switched Optical Network (ASON) architecture. ASTN and ASON essentially relate to the same network architecture.
Document ITU-T G.7713 “Distributed Call and Connection Management (DCM)” by the International Telecommunication Union (ITU) defines requirements for distributed calls and connection management of both the User Network Interface (UNI) and the Network Node Interface (NNI) in ASON/ASTN.
Document IETF/CCAMP RFC-4974 “Generalized MPLS (GMPLS) RSVP-TE Signalling Extensions in Support of Calls”, August 2007, by D. Papadimitriou and A. Farrel defines protocol procedures and extensions to support calls within networks using Generalized Multiprotocol Label Switching (GMPLS) protocols. In this document, a call is defined as an association between endpoints to support an instance of a network service. GMPLS can be used on a control plane for ASON/ASTN networks supporting DCM features. Accordingly, in communication networks supporting DCM features and using GMPLS protocols, a point-to-point call establishes a relationship between two endpoints based on which subsequent point-to-point connections may be generated.
Other communication technologies, like Multiprotocol Label Switching (MPLS) and Provider Backbone Bridging with Traffic Engineering (PBB-TE), support multipoint services in which more than two endpoints support an instance of a network service. However, the GMPLS point-to-point call concept does not support multipoint services using point-to-multipoint connections. In particular, the GMPLS point-to-point call concept does not support assigning multiple calls to the same network connection.